The objectve of this investigation was to explore the use of nonmyeloablative allogeneic peripheral blood stem cell tranplantation for treatment of hematologic diseases. Six patients were included: 3 cases with acute leukemia in first complete remission(2 AML and 1 ALL), 2 severe aplastic anemias and 1 chronic myeloid leukemia in chronic phase. All of the 6 cases were received HLA-identical siblings donor peripheral blood stem cell transplantation after a nonmyeloablative conditioning. The donor cells were engrafted in all patients(3 cases were full engrafment of donor cells and 3 were mixed chimerism). Hematopoietic recovery was appeared in all of the cases(ANC recovered to more than 0.5×10 9/L and platelet count to more than 30×10 9/L on day 9 to day 21 and day 14 to day 28 after transplantation, respectively). Two patients developed Ⅲ or Ⅳ degree GVHD. Our preliminary results suggest that the procedure is more safe, efficient and less complications than myeloablative conditioning regimens and represents another new approach in the management of patients with hematologic diseases.
